The disclosure relates generally to liquid cooled dynamoelectric devices, and more particularly, to a stator bar clip adaptor therefor.
Dynamoelectric devices include a stator that interacts with a rotor to create either a generator or a motor. The dynamoelectric interaction of the stator and rotor oftentimes requires cooling, which may be provided in the form of a liquid (e.g., a water-based coolant). Stators typically include a number of stator laminates that are coupled together. In order to provide the necessary liquid flow to the stator laminates for cooling, a stator bar clip is provided at the ends of the laminates. The stator bar clip holds the laminates together and provides a mechanism to deliver cooling liquid thereto. Stator bar clips take two predominate forms, depending on the form of stator laminates, referred to as bottle clips and leaf clips.
Referring to FIG. 1, a perspective view of a prior art liquid cooled dynamoelectric device 10 using stator bar bottle clips 12 is shown in a partially disassembled state. Stator bar bottle clips 12 include a stator bar coupling portion 14 that encloses the laminates (therein) of a stator bar (typically polygonal in shape) and is fluidly coupled to a port 16 (typically round in shape) that provides the cooling liquid to the stator laminates via piping 18 fluidly coupled to the rounded portion. Piping 18 also electrically couples adjacent bottle clips, e.g., 12A, 12B, to form the necessary electrical connections therebetween. Thus, bottle clips allow electrical connection to the stator laminates and liquid connection for cooling. As shown in FIG. 2, stator bar leaf clips 30 include a stator bar coupling portion 32 (typically polygonal) that encloses the stator laminates (therein) with a port 34 (typically round in shape) for liquid connection via piping for delivering a cooling liquid. A plurality of leafs 36 extend from stator bar coupling portion 32 and are bent to be interposed with an adjacent leaf clip's leafs to make an electrical connection with an adjacent leaf clip, e.g., 30A, 30B, and therefore the adjacent stator windings that require electrical connection.
As observed by comparing FIGS. 1 and 2, a dynamoelectric device is typically constructed with windings that accommodate either stator bar bottle clips or stator bar leaf clips, i.e., their use is mutually exclusive. Changing the type of clip typically requires rewinding the stator to change the configuration of stator bar laminates.
When a dynamoelectric device requires maintenance, its operation must stop so the system can be taken apart. Consequently, it is advantageous to minimize outage time as much as possible. For example, in terms of a generator, no electricity is generated during this time, so minimizing outage time is very advantageous. The need to minimize down time is especially important during a forced outage, e.g., when the device must stop for repair as opposed to a scheduled outage.
One challenge in minimizing outage time is that some repair and/or maintenance work requires removal of the stator bar clips. The stator bar clips can be removed by heating to reflow the brazing that holds them in place, or by cutting them. Regardless of technique used, the removed stator bar clips are usually dirty, which creates contamination issues when the clips must be re-brazed for re-installation. Cutting an end of the clip to remove the clip is typically impractical because, while it eliminates the contaminated copper and would allow contaminant-free re-brazing, it changes the overall length of the stator bar. In addition to the above-described challenges, the fact that the same type of stator bar clip must be used within a particular dynamoelectric device limits repair/maintenance options. For example, where a leaf clip type system is being repaired, only leaf clips can be reinstalled unless a very expensive and time consuming re-winding of the system to change the type of stator laminate configuration is performed. Similarly, where a bottle clip system is being repaired, only bottle clips can currently be used.